The present invention relates to a fuel supply apparatus of an outboard motor.
A fuel supply apparatus for supplying a fuel to an engine of an outboard motor is provided with a vapor separator for removing bubbles in the fuel. The vapor separator is formed into a shape of a small tank and is provided at its upper portion with a bubble discharge valve, which is designed to be closed by utilizing a buoyancy of a float.
Bubbles included in a fuel rise to the fuel surface level in the vapor separator and are discharged from the bubble discharge valve into an intake passage or the like. If the fuel level rises in the vapor separator, the float rises and the bubble discharge valve is closed. Therefore, in a normal condition, because only the bubbles are discharged from the bubble discharge valve and the fuel itself does not flow out easily.
However, in a case where a fuel tank mounted in a body of a boat, i.e. hull, is disposed on a position higher than the location of the vapor separator, when the engine is stopped, the fuel level rises in the vapor separator simultaneously, and there is a possibility that a fuel may overflow from the bubble discharge valve.
In order to prevent such an inconvenience, it is necessary to extremely enhance a fabrication accuracy of the bubble discharge valve of the vapor separator, and to increase a size of the float which closes the bubble discharge valve so as to increase the buoyancy so that the properties for cutting of fuel when the bubble discharge valve is closed is enhanced. However, these measures increase the fabrication cost of the vapor separator, and a size of the vapor separator is unintentionally increased.
Alternatively, if a cock which is manually opened and closed is provided at downstream of the vapor discharge valve of the vapor separator so as to close the cock when the engine is stopped in operation, it is possible to prevent the overflow of fuel even if the properties for cutting of fuel of the bubble discharge valve may be deteriorated in some degrees. However, there are drawbacks that the manual opening and closing operations of the cock are troublesome, and if the cock is closed when the engine is started, a fuel can not be supplied from the fuel tank by a squeeze pump (manual compressor) or air in the vapor separator can not be removed.